* This class provides utilities for processing document content, titles, and digests,
 * handling text normalization, content extraction, and similar document hash encoding/decoding.
 * It also manages document processing requests and integrates with the crawler system.
 *
 */
public class DocumentHelper {
    private static final Logger logger = LogManager.getLogger(DocumentHelper.class);

    /** Prefix used for encoded similar document hashes */

 * thumbnail processing during indexing.
 *
 * <p>The IndexingHelper manages bulk operations, handles retries on failures,
 * and provides various query-based operations for document management.
 * It also integrates with the thumbnail generation system and handles
 * the cleanup of old documents during updates.</p>
 */
public class IndexingHelper {
    /** Logger for this class */

  /**
   * Returns {@code true} if a character sequence contains at least one matching BMP character.
   * Equivalent to {@code !matchesNoneOf(sequence)}.
   *
   * <p>The default implementation iterates over the sequence, invoking {@link #matches} for each
   * character, until this returns {@code true} or the end is reached.
   *
   * @param sequence the character sequence to examine, possibly empty

   * contains entries with duplicate keys (for example, if it is a {@code SortedMap} whose
   * comparator is not <i>consistent with equals</i>), the results of this method are undefined.
   *
   * <p>The returned {@code BiMap} iterates over entries in the same order as the {@code entrySet}
   * of the original map.
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is

        elements[index] = null;
        index++;
        return result;
      }
    };
  }

  /**
   * Combines two iterators into a single iterator. The returned iterator iterates across the
   * elements in {@code a}, followed by the elements in {@code b}. The source iterators are not
   * polled until necessary.
   *

   * specified is included. To create a copy of a {@code SortedSet} that preserves the comparator,
   * call {@link #copyOfSorted} instead. This method iterates over {@code elements} at most once.
   *
   * <p>Note that if {@code s} is a {@code Set<String>}, then {@code ImmutableSortedSet.copyOf(s)}

      }
    }

    /**
     * Returns a lower bound for {@link #size()} based on the sizes of the backing sets.
     *
     * <p>This is more efficient than {@link #size()}, which iterates over the entire {@link
     * SetView}.
     */
    abstract int minSize();

    /**
     * Returns the {@link #minSize()} of {@code set} if it is a {@link SetView}, or the exact {@link

        return kvMultimap;
      }
    }

    return fromMapEntries(multimap.asMap().entrySet(), null);
  }

  /**
   * Returns an immutable multimap containing the specified entries. The returned multimap iterates
   * over keys in the order they were first encountered in the input, and the values for each key
   * are iterated in the order they were encountered.
   *

          newEntries[outI++] = entries[inI];
        }
      }
      return newEntries;
    }
  }

  /**
   * Returns an immutable map containing the same entries as {@code map}. The returned map iterates
   * over entries in the same order as the {@code entrySet} of the original map. If {@code map}
   * somehow contains entries with duplicate keys (for example, if it is a {@code SortedMap} whose

        return kvMultimap;
      }
    }

    return fromMapEntries(multimap.asMap().entrySet(), null);
  }

  /**
   * Returns an immutable multimap containing the specified entries. The returned multimap iterates
   * over keys in the order they were first encountered in the input, and the values for each key
   * are iterated in the order they were encountered.
   *